Hatcher-Algebraic-Topology · Problem 2.2.9

Homology

Mathematics — Graph Theory · cellular-homology-computation

Problem

Compute the homology groups of the following 2-complexes: (a) The quotient of S2S^2 obtained by identifying north and south poles to a point. (b) S1×(S1∨S1)S^1 \times (S^1 \vee S^1). (c) The space obtained from D2D^2 by first deleting the interiors of two disjoint subdisks in the interior of D2D^2 and then identifying all three resulting boundary circles together via homeomorphisms preserving clockwise orientations of these circles. (d) The quotient space of S1×S1S^1 \times S^1 obtained by identifying points in the circle S1×{x0}S^1 \times \{x_0\} that differ by 2π/m2\pi/m rotation and identifying points in the circle {x0}×S1\{x_0\} \times S^1 that differ by 2π/n2\pi/n rotation.

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